Apparatuses of this kind are manufactured for the preparation of specimens, in particular for the production of microtome sections. For this, tissue specimens to be examined are, for example, embedded in synthetic resin and these specimens are processed by means of milling cutters into the shape of truncated pyramids. These trimmed specimens are then sectioned in a microtome, thereby yielding tissue sections having a thickness in the micrometer or nanometer range that can then be examined.
The assignee of the present application has developed a unit that is suitable for such tasks and is already on the market. This unit additionally comprises an observation device with which the specimen can also be observed during processing.
These units are not suitable, however, for specimens made of harder material. For example, semiconductor materials such as silicon, gallium arsenide, and the like cannot be milled; other tools, in particular saws, are necessary for them.
An automatic sawing apparatus is disclosed, for example, in U.S. Pat. No. 5,456,147, the specimen to be processed being mounted on a movable arm and being brought via a positive guidance system into contact with the saw wheel, which rotates about its axis but is otherwise mounted rigidly in the housing of the apparatus.
A disadvantage of such systems is that the specimen is moved during processing, and observation of the specimen during processing is therefore not possible. The positive guidance system can moreover, for example, impose too great an advance which causes undesirable tensile forces; this can negatively affect the quality of the cut and, in the worst case, result in destruction of the specimen. Complex monitoring devices that measure the pressure loads on the saw and specimen arm are therefore necessary in order to protect the specimen and/or the saw wheel.